First impression can come in a few ways:
1) When you first see a person for the first time.
2) What you heard about a person. whether you know them or not.
3) When you think you know a person after a few hour @ day.
Me, I don't like to give a first impression on a person I only met for the first time. So, whenever people asks me what I think about them when I first saw them, I would just say "You seem okay".
The truth is, when I first met someone, I usually don't remember them too well. Not their name, nor their face. I may, sometimes remember you after a long time of what you were wearing, or holding or doing when I first saw you. That is only, if I ever become close to you.
There is this girl in my campus. I'm close to her now. We've been friends since our first semester here. After a year and a half of being friends, I suddenly remember, during orientation week, there was this girl sitting next to me carrying the same bag my friend did. That's when it came to me "Oh, it was her then".
Then, there is the chain of first impression.
A friend of yours met someone. A new 'friend'. Then, when your friend came back, they will tell you everything of that person. Whether its love, hate, annoyed, blank or stupid and the list goes on and on. That's your friend first impression on he/she. But listening to their story, you'll feel like you already know he/she and you felt the same way as your friend. Your friend first impression was chained down to you.
It's like the feeling of hatred you felt when a friend told you about someone the loath. Without knowing who that person really is, you felt the same way as your friend, minus the real experience.
That's how the chain works.
I really don't like it when someone bad mouth a person they just knew.
You come back from wherever you were and you just bad mouth someone who, for a few hours, you think is lame, weird and a loser. Its not that I never bad mouth someone. Its just that I don't bad mouth them immediately after I came back from that first meeting. Its just rude. Even a whole year wouldn't be enough for me to really get to know someone.
This is why I'm super careful when choosing friend. By just listening at how they talk to you after some time of knowing each other, you can easily know.
If they came home and bad mouth a friend of him/her, how can I be sure he/her didn't do the same thing to me before?
Anyway, this is just an opinion from my point of view. You may have your own.
Don't bash me for wanting to voice out my own.